Article VIII. Alternative or Unconventional Systems
13.20.570 Holding tanks.
A. Approval for use. Due to the unique circumstances of a holding tank, it shall be used as an onsite wastewater disposal system only as a last resort. The Director shall approve in writing, on a form to be attached to the building permit, the circumstances under which a holding tank will be accepted, including an agreement to pay an observation fee. Included in this form will be the requirement for periodic observations by the Director and the offsite location of waste disposal. An onsite wastewater system construction permit will be issued only when these additional requirements are met. Holding tanks shall not be used without an onsite wastewater system operating permit, the terms, conditions, and effective period of which shall be limited solely to the temporary use of the holding tank.
B. Requirements for holding tanks. The requirements for holding tanks are as follows:
1. The minimum liquid holding capacity shall be 1,000 gallons, or the wastewater flow generated over a period of 7 days, whichever is greater. There shall be no discharge of effluent from the tank (Note: In addition to number 1. above, the tank shall be sized to incorporate a 25% addition of projected sewage flows as a buffer in case of weather conditions, temporary unavailability of a liquid waste hauler, and other adverse conditions. Tanks at 75% of overflow capacity shall be considered to be full.);
2. The tank shall be equipped with a high-water alarm positioned to allow at least 3 days of storage after the alarm is activated. The alarm shall be placed in a location of easy recognition, and shall be labeled “alarm-sewage holding tank.”
3. Holding tanks shall conform to the requirements for septic tanks under ARSD § 74:53:01:23 (1) to (3) inclusive, with the exception of outlet devices. Tanks shall be fitted with easily accessible inspection holes for maintenance and pumpage. The inlet fixture and openings shall be properly sealed to assure watertightness of the tank. Baffle walls are not required in holding tanks.
4. Holding tanks shall be installed to meet the requirements for septic tanks under ARSD § 74:53:01:24.
C. Maintenance of holding tanks. The conditions of use which may be prescribed by the Director on a onsite wastewater system operating permit may include, but not be limited to, the requirement that the owner/user:
1. Contract with a liquid waste hauler. The contract shall provide that the hauler maintain and make available to the Director a record of pumping activities at the site;
2. Deliver to the Director, on a quarterly basis, copies of the liquid waste hauler’s weekly bills, statements, or invoices; and
3. Provide written authorization to allow the Director to initiate required maintenance at the owner/user’s expense, if noncompliance with these rules or legal notices results in an imminent threat to public health or safety.